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Commit 597fe310 authored by Shinya Kuribayashi's avatar Shinya Kuribayashi Committed by Ben Dooks
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i2c-designware: Skip RX_FULL and TX_EMPTY bits on tx abort errors 



Suppose TX_ABRT occurs in the middle of processing i2c_msg msgs[], and
a STOP condition has already been generated on the bus.  In this case,
subsequent i2c_dw_xfer_msg() might initiate a new and unnecessary I2C
transaction, which we'd have to avoid.

Furthermore, anytime TX_ABRT is set, the contents of tx/rx buffers are
flushed, so we don't have to process RX_FULL and TX_EMPTY.

Disable interrupts, and skip them.

Signed-off-by: default avatarShinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 8f588e40

drivers/i2c/busses/i2c-designware.c

+8 −0
Original line number Original line Diff line number Diff line
@@ -621,6 +621,13 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) 
	if (stat & DW_IC_INTR_TX_ABRT) {

	if (stat & DW_IC_INTR_TX_ABRT) {

		dev->cmd_err |= DW_IC_ERR_TX_ABRT;

		dev->cmd_err |= DW_IC_ERR_TX_ABRT;

		dev->status = STATUS_IDLE;

		dev->status = STATUS_IDLE;



		/*

		 * Anytime TX_ABRT is set, the contents of the tx/rx

		 * buffers are flushed.  Make sure to skip them.

		 */

		writel(0, dev->base + DW_IC_INTR_MASK);

		goto tx_aborted;

	}

	}





	if (stat & DW_IC_INTR_RX_FULL)

	if (stat & DW_IC_INTR_RX_FULL)
@@ -635,6 +642,7 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) 
	 * the current transmit status.

	 * the current transmit status.

	 */

	 */





tx_aborted:

	if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)

	if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)

		complete(&dev->cmd_complete);

		complete(&dev->cmd_complete);